Silicone has several DIY uses, the main one being to seal gaps where a flexible waterproof seal is required.

Uses

Life Expectancy

Silicone that does not dry out fully each day is prone to go mouldy, and mould is tough to remove from silicone.

Mould resistant silicones are available, and are generally the ones to choose.

Applicators make getting the sealant neat much easier. They receive good reviews on news:uk.d-i-y.

Home made applicators can also be made from polypropylene. They neeed to be feathered to give a suitable profile.